Thinner tire OK? Best tire for my conditions?

Most threads on tires talk about going BIGGER. I want to go smaller for less cost (I hope) and lower rolling resistance for (hopefully) better gas mileage.

I've got a 2003 4WD Taco with stock tire size 265 70/16. I bought it used with 265 75/16's. I'm going to be carrying a "lightweight" camper (yes, I've read all the threads about carrying maximum or more weight) during the summer months so will be needing D-rated tires. I'll be traveling forest roads with the camper, then dealing with occasional deep snow in the winter here in Colorado.

When I purchased the truck used, I was ignorant about tire size and gearing. Though I still don't completely understand how tire size can alter engine power, I do understand from other threads that changing the tire "height" alters the gearing, which is a problem. So my hope of just putting on 225 75/15 tires/wheels that other stock Tacos came with were dashed once I learned about gearing.

But can I go thinner? It looks like in D-rated 70 or 75/16 tires, manufactures offer 225's. One reputable tire dealer suggested 245's were better for off-roading than 265's (not sure why) but I'm not seeing that size amongst the major brands.

I'd also like any feedback about specific tires. I don't care about looks (I know. Sacrilegious on this forum.) but I do want a long-lasting tire. Most of the year, I'll be on dry pavement. Snow is a given in winter, though it doesn't last long enough to warrant dedicated snow tires. Here in the Rockies, we have sharp rocks. I don't plan on driving on sand (I wish I DID live close to an ocean.) I WILL encounter wet clay on occasion.

My choices appear to be:
BF Goodrich All Terrain (though it's probably too expensive)
Bridgestone Dueler
Kumho Road Venture
Yokohama Geolander
Others?

THANKS for your advice.

 

Correction. I'm wondering if 245 75R16 would be OK or even better than 265 75R16 that would be another comparable for my stock size 265 70R16 tires for the conditions listed previously.

I'm down to choosing between the Kumho Road Venture KL61's, the Yokohama Geolanders or the Goodyear Duratracs. Your thoughts?

P.S. Did I say something wrong in my first post that I'm not getting any responses?

 

I'm not sure it would really help with fuel. The limited 4runners come with 245's and there improved mpg over the tacoma is mostly from the new 4.0.

 

Running a more narrow tire will definitely help improve your mpg's. For two reasons, The narrow tires will weigh less probably 16 lbs per tire less.